Show simple item record

dc.contributor.advisorNunes, Suzana Pereira
dc.contributor.authorMoreno Chaparro, Nicolas
dc.date.accessioned2016-06-06T09:32:31Z
dc.date.available2016-06-06T09:32:31Z
dc.date.issued2016-05
dc.identifier.doi10.25781/KAUST-8Q4B5
dc.identifier.urihttp://hdl.handle.net/10754/611794
dc.description.abstractIsoporous membranes manufactured from diblock copolymer are successfully produced at laboratory scale under controlled conditions. Because of the complex phenomena involved, membrane preparation requires trial and error methodologies to find the optimal conditions, leading to a considerable demand of resources. Experimental insights demonstrate that the self-assembly of the block copolymers in solution has an effect on the final membrane structure. Nevertheless, the complete understanding of these multi-scale phenomena is elusive. Herein we use the coarse-grained method Dissipative Particle Dynamics to study the self-assembly of block copolymers that are used for the preparation of the membranes. To simulate representative time and length scales, we introduce a framework for model reduction of polymer chain representations for dissipative particle dynamics, which preserves the properties governing the phase equilibria. We reduce the number of degrees of freedom by accounting for the correlation between beads in fine-grained models via power laws and the consistent scaling of the simulation parameters. The coarse-graining models are consistent with the experimental evidence, showing a morphological transition of the aggregates as the polymer concentration and solvent affinity change. We show that hexagonal packing of the micelles can occur in solution within different windows of polymer concentration depending on the solvent affinity. However, the shape and size dispersion of the micelles determine the characteristic arrangement. We describe the order of crew-cut micelles using a rigid-sphere approximation and propose different phase parameters that characterize the emergence of monodisperse-spherical micelles in solution. Additionally, we investigate the effect of blending asymmetric diblock copolymers (AB/AC) over the properties of the membranes. We observe that the co-assembly mechanism localizes the AC molecules at the interface of A and B domains, and induces the swelling of the B-rich domains. The B-C interactions control the curvature of the assemblies in these blends. Finally, we study the self-assembly triblock copolymers used for membranes fabrication. We show that the polymer concentration, the block-copolymer composition, and the swelling of the micelle are responsible for the formation of elongated micelles in the casting solution. The formation of nanoporous membranes arises from the network-like packing of those micelles.
dc.language.isoen
dc.subjectSefl-asembly
dc.subjectBlock Copolymer
dc.subjectDissipative Particle Dynamics
dc.subjectCoarse-graining
dc.subjectmicelles
dc.titleMeso-scale Modeling of Block Copolymers Self-Assembly in Casting Solutions for Membrane Manufacture
dc.typeDissertation
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberCalo, Victor M.
dc.contributor.committeememberSaikaly, Pascal
dc.contributor.committeememberSpontak, Richard
dc.contributor.committeememberGomez, Diogo
thesis.degree.disciplineEnvironmental Science and Engineering
thesis.degree.nameDoctor of Philosophy
refterms.dateFOA2017-06-06T00:00:00Z


Files in this item

Thumbnail
Name:
Nicolas Moreno Chapparo Dissertation.pdf
Size:
25.96Mb
Format:
PDF
Description:
Nicolas Moreno Chapparo Dissertation

This item appears in the following Collection(s)

Show simple item record